The present invention relates to an image recording apparatus for use in copying machines, printers, and facsimiles, etc.
As described in a U.S. Pat. No. 3,689,935, in the image recording apparatus of this kind, electric potential is applied to a selected one of the plurality of aperture electrodes in accordance with image data, so that the charged toners pass through the aperture electrode to form a toner image onto an image receiving member provided on an opposing electrode.
The apparatus described provides a flat plate formed of a dielectric material, a continuous conductive reference electrode provided at one surface of the plate, and a plurality of control electrodes consisting of a plurality of insulatively isolated conductive segments provided at the opposite surface of the plate. Aperture penetrates through the flat plate, the continuous conductive electrode and the control electrode to provide at least one row of the aperture electrodes. The apparatus further includes means for selectively applying electric potentials between the reference electrode and the control electrode, means for projecting charged toners through the aperture whereby flow of the toners is modulated according to the potentials, and means for positioning the image receiving member in the path of flow of the toners so as to provide relative translation between the image receiving member and the aperture electrode.
U.S. Pat. Nos. 4,743,926, 4,755,837, 4,780,733 and 4,814,796 disclose an image recording apparatus in which control electrode faces the image receiving member and the reference electrode faces the toner supply means. On the other hand, U.S. Pat. No. 4,912,489 discloses the reference electrode facing the image receiving member and the control electrode facing the toner supply means. With this arrangement, electric voltage applied to the control electrode could be reduced to approximately one to four at OFF state in comparison with the aperture electrode having the reverse arrangement such as the above U.S. Pat. No. '926. Here, OFF state implies no toner attachment to the image receiving member for providing a non-imaged area. Reversely, ON state implies the toner image forming state.
However, according to the above described conventional image recording apparatus, it would be rather difficult to mount the aperture electrode body onto a main body in a desirable mode. That is, the aperture electrode body is formed of a thin film such as 25 micron meters thickness. Therefore, it would be difficult to provide a contact of the aperture electrode body with a toner carrier roller without any wrinkle while applying a tension to the aperture electrode body. If such contact is not provided, contacting condition between the aperture electrode body and the toner carrier roller may be varied, to degrade the imaging quality.